Infinitely variable power transmission control system



Aug. 24, 1965 z. J. JANIA 3,202,012

INFINITELY VARIABLE POWER TRANSMISSION CONTROL SYSTEM Filed Oct. 10, 1965 6 Sheets-Sheet 1 Z. J. JANIA INFINITELY VARIABLE POWER TRANSMISSION CONTROL SYSTEM Filed 0G12. l0, 1965 6 Sheets-Sheet 2 4( A m WEE-i# m M M W/ Aug. 24, 1965 z. J. JAMA 3,202,012

INFINITELY VARIABLE POWER TRANSMISSION CONTROL SYSTEM Filed Oct. lO, 1963 6 Sheets-Sheet 5 lkml. w

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m T m V m m M d d W u N m 0 ZY B Aug. 24, 1965 z. J. JANIA INFINITELY VARIABLE POWER TRANSMISSION .CONTROL- SYSTEM Filed Oct. l0, 1963 6 Sheets-Sheet 6 United States Patent O 3,202,012 INFINITELY VARIABLE POWER TRANS- MISSION CQNTROL SYSTEM Zbigniew J. Jania, Detroit, Mich., assignor to Ford Motor Company, Dearborn, Mich., a corporation of Delaware Filed Oct. 10, 1963, Ser. No. 315,266 klf2 Claims. (Cl. 74-472) My invention relates generally to a power transmission mechanism having `an infinitely variable torque ratio characteristic, and more particularly to a .control system for -use with an infinitely variable .torque ratio drive in an automotive vehicle driveline.

I contemplate that the improvements of my invention can be applied to yan infinitely variable torque ratio drive mechanism in a driveline that includes a throttle controlled internal combustion engine. According to a principal feature of my invention, the operating characteristics of the drive are sensed by the control system which responds by appropriately changing the speed ratio of the drive for any given load and for any given demand for engine torque that may be imposed by the operator. The over-all operating performance of the driveline thus may be characterized by a maximum degree of engine fuel economy for all driving conditions.

It is well known that the operating efficiency of an internal combustion engine of the piston type, as measured by the specific fuel consumption, may .vary within wide limits during operation as the operating conditions are varied. The horsepower requirements of the engine, of course, are determined by the road conditions, such as the grade, mechanical friction, aerodynamic drag, etc., lfor any given vehicle speed. The vehicle speed that is `selected by the vehicle operator will be accompanied by .a corresponding load imposed by the road conditions at that speed. Each selected vehicle speed can be achieved with any of a variety of engine speeds, and the engine speed in turn depends upon the speed ratio of the drive with which the engine is used. Each engine speed, of course, results in .a different brake specific fuel consumption for the driving conditions that prevail. It is desirable, therefore, to properly match the engine and variable speed ratio drive to obtain a minimum brake specific fuel consumption for each vehicle speed selected by the operator and for each corresponding road load. More precisely, the fuel economy, as determined in part by the ratio of transmission efH-ciency to brake specific fuel consumption, should be made a maximum by providing a control systern that will respond to control variables to produce a maximum value at that ratio for each road load. Since the transmission efficiency may vary as the engine power changes, it may be desirable to choose a value for brake specific fuel consumption that is slightly different than the minimum value to compensate for any adverse influence on transmission eiciency. The control system then can be calibrated accordingly. The term transmission efficiency, as used in this description, means that factor by which the horsepower input to the transmission must be multiplied to produce the actual shaft horsepower on the power output end of the transmission.

In accomplishing .the foregoing objective, I have provided a control system that will yallow the. speed of the engine to be maintained at a constant value for any given demand for engine torque by the vehicle operator. In the case of a throttle controlled internal combustion engine, the driver demand for engine -torque is related in magnitude to the position of the vehicle accelerator link- :age which in turn is mechanically connected to the engine throttle valve. My improved system will cause simultaneously the engine throttle valve to assume a setting that will allow the engine to .operate with a minimum ice brake specific fuel consumption for the prevailing vehicle speed and road load. The vehicle speed for any given accelerator position .then is determined by the road conditions` and the vehicle opera-tor can select the speed as road conditions change simply by controlling the position of the `accelerator linkage. The provision of a control system of this type is a principal object of my invention.

It is necessary in such a control system to measure engine speed by means of an appropriate speed sensing mechanism and o make provision for comparing that engine speed with the speed that is demanded by the vehicle operator. The difference between the actual speed Iand the so-called comman speed is amplified and then sensed by the control system so that an appropriate speed ratio change in the drive can be accomplished. The engine speed thus is maintained at a constant value. The control system also must adjust the engine carburetor throttle position for the corresponding corrected engine speed that is established. The value of the engine carburetor throttle position then -must be related functionally to the speed-torque characteristics of .the engine and the road load requirements as well `as the vehicle weight and other physical vehicle characteristics. The provision of a control system that will function in this fashion is another object of my invention.

In measuring the engine speed I employ an engine driven fluid pressure governor that establishes a fluid pressure signal that is related in magnitude to the engine speed. The actual value of the speed signal is proportional to the square of the engine speed. The control system, however, requires ya linear speed signal as it. influences the ratio changing structure of the drive. It is `an object of my invention, therefore, to provide a means for modifying the non-linear signal produced by the governor mechanism so that the resulting signal that is transmitted to the drive ratio controlling system will be related linearly to engine speed.

I contemplate that my improved control system will allow the vehicle operator to obtain a rapid increase in torque ratio `as he demands more torque by advancing rapidly the accelerator linkage to an advanced engine throttle kickdown position. This, of course, causes an immediate adjustment of the engine carburetor throttle valve, but the inertia of the engine results in a delayed response of the engine. The response of the control system to this demand for increased torque, in contrast, is relatively instantaneous. lIt is another object of my invention, therefore, to provide a mechanical time delay network that will Ifunction to synchronize the responses of the engine and the control system and in this way avoid :an undesirable sharp deceleration of the vehicle for a short period of time after lthe acceleration linkage is advanced to the so-called kickdown position.

It is another object of my invention to provide a control system yfor `an infinitely variable drive of the type above set forth wherein provision is made for overruling the automatic drive ratio controlling elements when coast braking is desired. The infinitely variable drive thus can be used to provide an optimum degree of engine braking for any given vehicle speed.

It is another object of my invention to provide a control system ofthe type above set forth wherein the vehicle wheel brakes are caused to `function in cooperation with the coast brake controlling elements `of the drive so that the degree of coast braking provided by the drive is reiated in magnitude tothe degree of braking effort imposed by the vehicle operator on the vehicle wheel brakes.

Further objects and features of my invention will be- -come apparent from the following description and from the accompanying drawings, wherein:

FIGURE l shows in cross sectional form an infinitely variable friction disc drive that embo ies the improvements of rny invention;l Y

FIGURE 2 is a transverse 4cross sectional view taken along the, plane of section line 2-2 of ,FIGURE 1';

FIGURE 3 is la performance curveV for al typical internal combustion vehicle engine in an `automotive vehicle drivelne; l Y. H y FIGURE 4 isfa schematic view showingfcertancomare `situated in interdigital krelationship with respect to internally splined discs 98. Theseare carriedrby an externally splined clutch member 100 that is connected y directlyto a central torque delivery shaft 102. The leftuponents of a control system 'for the vmechanism `of FIG- i URES land 2;'

FIGURE/5 is a l tions of axcontrol system embodying the improvements of my invention; and

`block diagramillustrating the' func-V f FIGUREA 6 is an/illustration in schematic form of'an operating embodiment'of the system shown in FIGURE 5; and

FIGURES-7 and 8 illustratethe cam geometry for the operator controlled accelerator linkage.

Referring rst to FIGURE 1, numeral 10 designates in f e general a hydrokinetic uid coupling having a bladed impeller 12 and a cooperating bladed turbineV 14. The impeller' and Vthe turbine are situated in juxtaposed fluid iiow 'relationship land are enclosed by' a coupling impeller shell having two torus-shaped parts '16 and 18.* Each shell part is formed with a peripheral iiange to permit a Welded connection between them.

' `An impeller shroud 20 'is riveted or otherwise securedy -at '22 to the hub 24 of impeller shellV part 16. In a sinular fashion, a turbine, shroud 26 is secured by rivets 28 ,to the' hub 30 of the bladed impeller 14. Shroud`20has secured thereto Vradially disposed impeller blades that are secured in place by means of tabs 32. The turbine blades of the-turbine 14 similarly are', provided with tabsr3r4 to permit a connection with the shroud V26. A a

Hub 24 of the shell part 16 is'splined aty 36 toa torsional damper assembly 38. `This assembly isboltedby kmeans of `bolts40 to a drive plate 42, the outer periphery of which carries an engine starter motor ringgear 44.

The'inner periphery of drive plate 42 is formed with bolt l openings '46 to "permit a bolted connection with a flange formed on the crankshaft ofan internal coinlnistionV vehicleengine. Y

' Coupling 10 is disposed Within.v housing portionS which maybe secured 'at its periphery to the engine block ofthe internal combustion engine. Housing 48 includes a wall 50 to which is secured a frontpump housing Positivedisplacement pump 'gears v54 and 56 are situated within a pump cavity 58 formed in thev housing 52.

Gear 56 is'splined at 60 to the hub62 of shell part 18. Hub 30 oftheturbine V14 is'v connected directly'to a turbine sleeve shaft 64 which extends through pumpgear element 56 in the Wall 50.

A simple planetary gear unit is identified generally by reference character 66. It includesfa sunv gear 68, a ring gear 'and'a plurality of planet pinions y72.V Pinions 72 are carriedV byA a carrier 74 having pinion shafts 76 upon which the pinions 72'are journaled. Carrier 74 defines a brake drum 78 upon which is positioned a reverse brake band 80; A suitable iuid pressure operated brake servo canbeernployed for applying and releasing the brake 80 thereby anchoring selectively the carrier 74;

kCarrier 74 has secured thereto an end plate 82. Itrcooperates with th'eplate' 82 to deiinefan annularV cylinder 84 within which is positioned an annular piston 86. Situated directly adjacent the piston 86 is a friction clutch disc 88 having a hub 90 that'is splined to the sleeve Ashaft' k64. A back-up frictionV disc 92V also is carried bythe establishing `a direct connection between the carrier 74 and the sleeve'shaft 64. l

"A clutch drum 941is connecteddir'ectly tothe carrier; '5

74. It is internally splinedpto permit a driving lconnectionwith externally splined clutch'dis'csi.' The discs .ring 70, and surrounds `r the-drum l94.

',.isheldx axially fast lwith respect-thereto by snapl ring 108. VCylinder106 isf providedrwiuth a hub 110 that is journaled rotatably upon a central torquedelivery shaft`112. Disposedkwithin the" cylinder '1061is' an .annular piston 114 which cooperates with the cylinder `106 to define apressure cavity'I Fluid under pressure; can be admitted to the cavity through a port l1161 Vwhich communicates with a Ycentral passage V118. Passage; 11,8 in turn communicates with'a port 120 formed in adsleeve 122 which is splined at 124 to the 'shaft 112. The sleeve 122 in turn is journaledwithin a centralfopenin'g A17.6 formed in the separatling`wall`l28`; This wallforms a separation between an lintermediate housing `portion 13 0and a" main housing portion 132. f y p A torque transfer drum 134 is connected directly to It is keyed or rsplined to the periphery of a drive vmember ,136 which is connected directly to the sleeve 120. y 1 .v A piston returnV spring 138isy situated between the piston 114 and afspring seat-'140 carried by the: hub 110 of thecylinder 106. As iiuid pressure is admitted to the annular cavity defined by the cylinder 106 and-the piston' 114, the friction discs Q8 and 96 engageeachother thereby establishing a direct connection between shaftf102 and the carrier 7 4.

connection with internally splinedfriction discs 150 and 1752. The discs Vand 1521are situated infpairs in Stacked relationship. onv the shaft 112. They are held axially fast Vbyrspaced` snapfrings 154 and156. Each Y disc 150 and 152 is formed with a conical shape and their outer peripheries are adapted to engage i coned shaped friction discs 158 thaty are keyed Vor splined to -a socalled carrier shaft i160. As best viewed in FIGURE Z, there are three shafts-situated in annularlyl spaced relationship abouttheaxis of shaft 112. .v Each shaft 160 carries a-plurality ofl discs 158. v v- The periphery of discs 150 engages one side'ofits associateddiscsV 158 and the periphery of discs ISZengages the otherside ofthe associateddiscs 15S.- The resiliency ofthe discs 150 Vand 152 causes a clamping pressure to be exerted upon the discs 158 so that a frictional driving 1 and 164.` These discs, like thedisc's 150 and 152, are in `thelforrn of BeHeville springs and their inner peripheries engage opposed sides of the'friction surfaces of the discs 158. They are situated iny pairs and a frictionai driving connection is established Vbetweeneach disc 158 and each! pairof discs 162 and'164. The resiliency of the discs- 162 and'164 establishes anfappropriate clamping pressure to maintain this driving relationship.V i l Situated within the housing Aportion 1321is a carrier cette. 16.6. having 4axially Aspaced, Abearing 1 portions in' ther form of circular bosses 168Vand` 170. The@4 bosses` are;

. 176. A concentrically disposed cage 178 surrounds cage 166 and includes bearing portions 180 and 182 which are slidably disposed upon bearing surfaces 174 and 176, respectively. These bearing portions 180 and 182 are circular in form and are interconnected by web members 184 to form an integral assembly.

Boss 176 of cage 166 is secured fast to the wall 128 by means of bolts 186.

Bosses 18) and 182 are formed with external teeth which engage the internal teeth of a ring gear 188. This ring gear is concentrically positioned with respect to the shaft 112 and is supported by the cage 178. A lug in the form of an eyelet 190 extends from ring gear 188 and is pinned or otherwise linked to a control rod 192 as best viewed in FIGURE 2. One end of rod 192 is pinned or otherwise connected to a piston rod 194 which is carried by a fluid pressure operated piston 196. Piston 196 is slidably disposed Within an annular cylinder 198 that is formed in and defined by housing portion 132.

The open end of the cylinder 198 is closed by a closure member 132'. A pair of working chambers is defined by the piston 196 and the cylinder 198, one chamber being situated on either side of the piston 196.

Each shaft 160 is end supported by means of arms 200 and 262. These arms are formed with bearing openings for receiving bushings that journal the ends of shafts 160.

One end of each arm 200 and 202 carries a pinion. Each pinion is xed to its associated arm so that the two rotate in unison. The pinion associated with arm 200 is identified in FIGURES 1 and 2 by reference character 264, and the corresponding pinion for the arm 262 is shown at 206 in FIGURE l. Pinion 204 and its associated arm 266 are journaled upon a pinion shaft 208 which is carried by the boss 170. In a similar fashion pinion 206 is journaled upon a pinion shaft, not shown, that in turn is supported by boss 168.

It will be apparent from the foregoing that as the piston 196 is adjusted under the influence of uid pressure admitted to the working chambers in the cylinder 198, the linear motion of the piston will be translated into rotary motion of the ring gear 188. This in turn will cause pinions 204 and 206 to rotate which results in radial adjustment of the carrier shaft 160.

There are three shafts 160 as best seen in FIGURE 2, each shaft carrying a set of conical carrier discs. These `shafts have been identified by identical reference characwhich is journaled within a bearing opening 212 in one end of the housing portion 132.

During operation of the mechanism in the first forward driving range, the friction clutch shown in part at 188 is applied by introducing fluid pressure to the cylinder 84. Appropriate fluid passage means, not shown, can be provided for this purpose. The vehicle engine torque then is delivered through the fluid coupling 10 to the turbine shaft 64. The elements of the planetary gear unit y66 rotate in unison under these conditions since sun gear 68 is connected directly to the disc 88 and, hence, to the shaft 64. Engine torque then is delivered to the ring gear 76 and is distributed through the drum 134 to the shaft 112. Driving torque then is transmitted to the sun discs which cause the carrier discs to rotate about the axes of their respective shafts 160. The carrier discs k1,58 then drive the ring discs thus causing the drum and power output shaft 210 to rotate in a direction opposite the direction of rotation of the sun discs.

The speed ratio of the disc drive mechanism is dependent, of course, upon the radial position of the shafts 166. In the position shown in FIGURE 1 the disc drive mechanism is conditioned for maximum speed reduction. On the other hand, if the shafts 160 are moved radially inwardly, the speed of rotation of the ring discs increases with respect to the speed of rotation of the sun discs.

The fluid coupling provides a hydrokinetic cushion in the driveline thus making possible a smooth start as the vehicle is accelerated. The fluid coupling also functions as a neutral clutch when the clutch mechanism shown in part at 88 remains applied as the vehicle engine is idling prior to acceleration from a standing start.

After the vehicle is under way, it is desirable to establish a direct connection between the engine crankshaft and the sun discs. This is accomplished by engaging the multiple disc clutch assembly shown in part at 96 and 98. The direct connection thus established between the impeller and the ring gear bypasses the hydrokinetic coupling 10 to create a wholly mechanical drive that improves cruising efficiency under steady-state road load conditions.

To establish reverse drive, both the friction clutches shown in part at 88 and at 96 and 98 are released while the brake band is applied. The carrier 74 thus becomes anchored. Engine torque then is delivered through the coupling l@ and the resulting turbine torque is delivered through shaft 64 directly to the sun gear 68. This causes reverse rotation of the ring gear 80 as the carrier 74 acts as a reaction member. The sun discs thus are driven in a reverse direction and this, of course, causes reverse rotation of the ring discs and the power output shaft 210. The overall speed ratio in the reverse drive range can be varied by appropriately adjusting the radial position of the shafts 160.

By appropriately matching the operating characteristics of the engine with the performance characteristics of the variable speed drive, the engine can be caused to operate at its most efficient speed for any given load. To illustrate this' design approach, I have shown in FIGURE 3 a graph in which engine speed is plotted against the brake specific fuel consumption for each of several constant values of brake horsepower. varied for any given brake horsepower, the brake specific fuel consumption will decrease progressively yuntil it reaches a minimum value. Upon further change in engine speed, the brake specific fuel consumption again will rise. In an ideal driveline the engine would be caused to operate at the minimum specific fuel consumption point for any given constant value of brake horsepower as the engine speed varies.

In FIGURE 3 I have shown a plot that illustrates the variation in brake specic fuel consumption for various engine speeds while the engine is operating at any of the several indicated horsepower ranges. Flor any given transmission that is used with the engine having the performance characteristics shown in FIGURE 3, there will be a certain engine speed corresponding to any given vehicle speed, the road load requirements at that speed being determined by the constant horsepower curves. For example, in the plot shown in FIGURE 3 there Ais shown in Curve A the performance characteristics obtained with a conventional hydrokinetic torque converter transmission commonly employed in the automotive industry when it is used with a 312 cubic inch throttle controlled internal combustion engine. It can be seen by re ferring to Curve A that at a vehicle speed of 40 miles per hour, for example, at which road load requirements are l5 horsepower, the brake specific fuel consumption is .7 lbs. per brake horsepower per hour. For purposes of comparison, We have shown also in FIGURE 3 the corresponding performance characteristics that would be obtained if the same engine were used with an ideal 100 percent efficient infinitely variable torque .ratio transmis- If the engine speed is sion.A 'This curve is identied. by the symbol' It is` anY envelope curve' that is tangentto theminimum Ybrake horsepower point for each constant'speciic fuel consumption curve. f The brake specic fuel consumption that is required to achieve a .vehicle speed of 40 vmiles per hour and. tosatisfy the horsepower roady load requirements at that speed is` equal'v to approximately .46 lbsper brake horsepower per hour. Y.

By employing the friction disc drive shown FIGURE 1 and by utilizing 4the improved control system of my in- 'substantially' lower than .theywo'uld be if'a transmission' having the characteristics of Curve Awere'used. It will be observed fromFIGURE 3.that the brake speci'c fuel consumption necessary 'to achieve a vehicle speed of40 miles per hourand to. satisfy .the brake horsepower imposed by 4the road conditions at that speedfis equal to approximately 55 lb.'per brake horsepower hour.

A pressure feed passage 262r communicates with the yannular cylinder 198 on -one'side of the piston 196.Y Another'pressure feed passage 264 communicates with the cylinder 198 on the-opposite side of the piston 196. The position ofthe piston 196, .and hence the position ofthe piston rod :194, j`is determined by the pressure distribution across the piston 196that isprovided by feed passy ages 262 Iand 264.. vPassage 264 communicates with valve chamber 242 at a location intermediate valve lands 236 and-238.y v v. v

An exhaust port for the pilot valve 230 isshown at 266.

' `It is in iluid communication with three vspaced exhaust groovesfo'rmed in opening 242 as indicated by 'refe-rence characters 268, 270 and27 2." Groove 272 normally is The left hand side of the land 234 is subjected to gov- -ernor pressure by' means of a governor pressure passage The curve .C shown in FIGURE 3 is achieved by maintaining the vspeed of theengine'constant at .any given accelerator linkage'position and. by 'allowing the carburetor'throttlevalve to be opened to a setting such that the. engine will operate at lthe j minimum possible brake specific fuel consumption point. VThis principle can be 274. This governor pressure Vcreates .a pressure force vthat tendsto urgethe spool 232'in a right 'hand direction against 'the opposing influence of spring 244. f

As the accelerator. pedal 212 iis. moved towards an advancedengine ,throttle position, the spring tensionV of spring l244 is increased thereby tending to shiftthevalve spool 23:2 in a left hand direction..jThis. tends to increase thel degree of.-communicationbe-tween passages 258 and 262 while simultaneously decreasing. the degree of communication between passa'ges 25S1and 264. This understood readily'by referring tothe schematic diagram f identifies-fan accelerator pedal that is under thecontrol of the vehicle operator. Itjis pivoted to the vehicle chassis at 214 and is connected by means of a .suitable linkagey 216 to a cam 21S. The Vcam'218 is'rotated Vas the accelerator pedal V212 is pvoted about the pivot 214. Y

A cam follower 220 lengages the c-am surface 222 .of the cam' 21'8r and it in turn causes a'carburetor throttle valve lever'wto rotate.V Thexcarburetor throttle for the engine `is shown at 224 and is mounted upon a throttle lever shafty 226 lthat is connected to the end of linkage 216. Throttle valve spring 2278y ,normally urges the throttle'224 -to an open positiom` Y 1 v l' The cam: 218 and the linkage 216 can becalibrated so that the engine will voperate at its minimum 'brake specific fuel consumption point for any given .accelerator position. The mechanism for providing. aV constant engine speedV at any given accelerator position includes a servopilot valve 23:0.`V This valve includes a multiple land valve spool 232 Vhaving spaced valve lands234,v 236,'.238 and 240.- These lands are slidably positioned within avalve chamber 242 having cooperating internal vvalvelandrs;y

is accompaniedsimultaneously by a'decrease 'in the degre-e of communication betweenfpassage 262 and exhaust groove 272 andan increase inthe degree of communication between passage 264 and 4exhaust groove 270. This yaction results in Aan increase inthe pressurejon the right hand sideof the piston 19.6 relative .to the pressure on the `left* hand'side thereof.v This of Vcoursetends to shift the pistonrod194 in aleft hand direction which tends tocause the `friction disc drive to decrease its `speedl ratio.A AAs soon as a reduction in the speed ratioisaccomplished, the ene -ginespeed tends to increase.`V` This of course'results in an increasein the-governor pressuremjade availableto passage 274, This tends to Vrestore the balancebetween the forces acting uponthe 'spool A232'sothat the pressure forces acting on either side; of the. piston 196 ragain will be stabilized `with the piston rod 194 in the adjusted position.

` `Of-courseif the -acceleratonpedatis backed off, the springypressure of spring 244visdecreased. This then re- .sults'in a Ydecrease in the pressurerof the righth-and side Spool 232 is urged normally in a left-hand direction as propriate linkage schematically designated at 248. Y

The engine driven'4 pump ,shown in FIGURE V1 fat'r54 and 56 is designated generally in schematic'form in FIG,-l URE 4 by reference Ycharacter 250. It is'providedf with a suitable intake passage252 and -a high pressure discharge of the piston' 196relative tothe., pressure that exists on displaced in a right hand'v direction las viewed in FIG- URE. `4 whichresults infan increase in speed ratio. This is accompanied by a' corresponding decrease in the. engine speed for any given road load. The resulting decrease in the governor pressurein passage 274then results'in a decrease Iin the governor pressure force acting upon the spool 232so that the pilot valve forces Vagain, become balanced as the 'piston 196 lassumes its new adjusted position. o V j i The governor pressure signal utilized 'by the pilot valve is obtained `by means of a. Vgovernor valve mechanism 276. 'It` includes a governor valve body 278 having a valve chamber280 within which isV slidably positioned a Y governorfvalve spool 282.'Y This spool includes spaced passage 254 A Vmain regulatoivalve 256 `maintains constant'regulated cpontr'ollpressure inv passage258'which communicates with passage 254. Regulator valve 256 v-acts as ahy-pass valve andthe by-pass liuid tlow is returnedv to the low pressure intake Ipassage'252-Kbymeans valve lands284, A236 and 288. Control .pressure from the passage'. AV258v is distributed to the-valve ychamber 280 through a' governor feedpassa'g'e 290, which communicates with the chamber 280 at a location directly adjacentland 286i- Exhaust port'292 communicates with .theV chamber 280 yat a' location intermediate Ilands 2858 and 286. Governor pressure passage 274 communicates with ythechamber 280 at a location intermediate lands`284 and 286-and yactsup'on a differential "area defined by Vthese lands to urge the-valve spood 282` normally in a radially centrifugal force acting upon the valve spool 282. Valve body 278 is mounted for rotation upon yan engine drive shaft in a suitable fashion or it may be connected directly yprovided a system which can be described in general terms by means of the block diagram of FIGURE 5. An operating embodiment `of the block diagram of FIGURE will 'be described subsequently with reference to FIG- URE 6.

As seen in FIGURE 5, the accelerator pedal is connected to the engine carburetor throttle valve by means of a suitable motion transmitting mechanism which will establish the proper functional relationship between accelerator pedal position and carburetor throttle ,opening to permit the engine to operate at its minimum brake specic fuel consumption point for any given engine speed. The motion of the accelerator pedal is transmitted also through an appropriate transducer and time delay system to a summing point which measures the variable command signal C made available by the vehicle operator through the medium of the accelerator pedal. The summing point receives also a feed-back signal from a speed sensing device of the type shown in FIGURE 4 at 276. The difference between the command signal C and the feed-back signal F is amplified by a signal amplifier and then distributed to a servo pilot valve of the type described With reference to FIGURE 4, for example. This pilot valve receives its control pressure Ps from a source such as the pump 250.

The servo valve then controls the position of the hydraulic servo motor which influences the I.V. transmission to cause the latter to vary its ratio to satisfy the engine requirements. The engine responds to the change in ratio of the transmission and this tends to result in a change in engine speed. The change in engine speed then is sensed by the speed sensing device and a feed back signal F then is supplied to the summing point.

If it is desired to overrule the command signal, a source of a constant command signal can be applied to the summing point by making an appropriate manual selection between the signal C and a constant command signal CC. This source of the constant command signal can be used, for example, when engine braking is desired.

Referring next to FIGURE 6, the command limiting or time constant network may include a dash pot 294 and a spring 296. The cam 218 may be mounted upon a cam rod 298 which carries a pinion 30). This pinion engages a rack 302 that is mechanically connected to the accelerator pedal 212 through the linkage mechanism 216. The cam surface 222 of the cam 218 engages a command push rod 304 slidably positioned Within a suitable pilot opening. Spring 2% is situated between the push rod 3M and a dash pot piston rodV 306. Rod 396 in turn is connected to the piston 308 of the dashpot 294.

The linkage 248 may be in the form of a lever that is pivoted at 310 to the piston rod 306. It is connected at its other end to the plunger 246 and spool 232 by an appropriate connection 312. An intermediate point 314 on the lever 248 is connected to a feed back piston 316 situated within the feed back cylinder 31S. A non-linear coilspring 325i is situated within the feed back cylinder 31S and acts upon the piston 316 to urge normally the lever 248 in a left hand direction. Governor pressure from governor valve mechanism 276 is distributed through l@ passage 274 to the left hand side of the feed back piston 316.

The cam contour of cam 218 can best be observed by referring to FIGURE 8. As the throttle angle x desired by the vehicle operator is fed into the cam 218, the command push rod is caused to be displaced a distance x. This distance is proportional to some command engine` speed which is predetermined after the engine characteristics are known so as to give the required horsepower under minimum brake specific fuel consumption conditions. The relationship between the angle a and the command engine speed Ne is illustrated in the chart of FIGURE 7.

The command push rod acts through the mechanical command limiting network and causes the spring 296 to become compressed. Initial motion of the upper end of lever 218 is delayed by reason of the action of the dash pot 294.

The pressure in passage 258 is indicated in FIGURE 6 by the symbol PS. An increase in engine throttle setting will tend to move the valve spool to cause an adjustment of the piston 196 to a position which will decrease the speed ratio of the friction disc drive. This causes the engine speed to change toward the-maximum economy point and this new engine speed results in a change in the governor pressure signal in passage 274. This is done by applying the governor pressure signal to the feed back cylinder 318 so that it urges the feed back piston 316 in a right hand direction as seen in FIGURE 6.

As explained previously, the governor pressure signal varies non-linearly with the engine speed. For this reason, a non-linear spring 32d must be employed so that the effect of the non-linear function of the governor pressure valve mechanism will be linear in character as it intiuences the pilot valve spool 232. The mechanical command limiting or time constant network is necessary in this arrangement to delay the effect of the command signal under kickdown conditions so that the effect of normal slower rate of response of the engine, as compared to the normal rate of response of the control system will be olfset. Thus the driveline will not lose power when acceleration is required. In one operating embodiment, a time constant of about one second has been found to be ample to compensate for the differences in the rates of response of the engine and of the control system.

To accomplish coast braking a signal from a command signal source is supplied to the feed back cylinder 318 through a regulator pressure passage 322. This passage communicates with a manual valve chamber 324 within which is positioned a manual valve spool 326 having spaced valve lands 323 and 330. A manually controlled lever 332 is provided for appropriately positioning the spool 326. Spool 326 normally is urged in a downward direction by valve spring 334, but it may be displaced in an upper direction by the lever 332 if this is desired by the operator. When the valve spool 326 assumes the position shown, passage 322 communicates with an exhaust port 336. As the spool 326 is moved upwardly, however, communication is established between passage 322 and the passage 338, which extends to a -hill retard or coast brake regulator valve chamber 340. Situated within chamber 340 is a valve spool 342 having spaced valve lands 344 and 346. Spool 342 includes an extension 348 that extends within a secondary valve chamber 350.

The vehicle wheel brake master cylinder 352 is pressurized by the vehicle operator by means of a conventional brake linkage mechanism 354 whenever vehicle braking is desired. This causes an increase in pressure in passage 356 which communicates with the master brake cylinder. This pressure is transmitted to chamber 350, thereby causing valve spool 342 to be urged in a righthand direction as viewed in FIGURE 6.

Pressure from the pump 254B is supplied to the valve chamber 340 through a port 358. An exhaust port 361 communicates with the chamber 340 at a location spaced fromAthe port 358i.' 'A spring 360 Lnormallyurgeslthe spool 342 4in alefthand direction .to Vdecrease the.y degree ly thereby allowing the pressure ,in passage v338 .tojbe Y made available to passage 322. This pressure inrturnV acts upon the .feed back piston 316 to supplement the action of the non-linear springf320. VThis forces thefric-y tion disck drive to assume an underdrive conditionrand the amount of the underdrive that is'established isV proportional Vto the difference between the pressurel in :the master Vbrake cylinder and the governor pressure in passage 274.

Having thus described a preferred form of my invention, what I claim anddesire to'secureby U;S Letters Patent is: y

` 1.,"In a driveline for a wheeled vehicle, an `internal combustion engine 4havin-g van/air-fuel. mixtureY intake manifold and a mixture fiow controllingthrottle valve,'an infinitely variablefriction drive comprising first friction elements drivably connected to said engine, lsecond friction elements connected to driven'portionsaof the driveline, third vfriction elements engage'able with both said first and said second friction elements and adaptedthere-` by to establish a frictional driving connection therebe-VV tween, fluid pressureoperated servomeans including a pressure operated piston for varying the'position of said third elements relative to saidv first and second elements thereby providing an infinitely variable speed ratio change, a fiuid pressure source, conduit structure interconnecting said source and said 4servo means, valve means disposed in and partly defining said conduit structure for distributing pressure to spaced portions yof saidservo means including an adjustable valve element adapted to effect a pressure unbalance across said piston in one -direction when it assumes one position and Yto effecta pressure unbalance across said piston in the opposite direction `when pressure operated pisto'nlfor `varying the" position ofV said third .elementsjrelative to said 'firstv and 'second` 'elements thereby providing an infinitely variable speed ratiorchange,

,a uid pressure source, conduit structurey interconnecting vsaidpsource vand 'saidservojmeand valve-means disposed in andpart1yV defining said conduit l.structure for distributing pressure tospaced portions of said servo means including an adjustable'valvelelement adapted to effect a pressure unbalance across 'said piston in yone direction 'when it assumes one position and to effect 'a pressure un- 'balance across said piston in the opposite directionjwhen it assumes anotherposition, a personally operable accelerator, a calibrated command mechanism interconnecting said Vthrottle valve 'and said accelerator whereby said engine isadapted toV operate, with the ratio of` transmission efiiciency to brake specific'fuel 'consumption at an approximatelyfmaximumi value for 'any given engine speed,.a.motion transmitting connection .between'said accelerator and said valve element for urgingV the latter in one direction with a force that is related functionally in magnitude Ato ,accelerator movement, an engine driven fluid pressure governor, a; feed back mechanism including a pressure sensitive member lconnected to said valve element, andpa fluid connection between said governor and said pressure sensitive member for subjecting the latter toa speed signal that opposesy the effect of the command signalimposedby saidcommand mechanism whereit assumes another position, a personally operable accelerator, a lcalibrated command mechanism interconnect-v ing said throttle valve and said accelerator whereby said engine is adapted to operate with the ratio of transmission efiiciency tobrake specific fuel consumptioniat an approximately maximum value for any given engine speed,

2.'In a driveline for a wheeled vehicle, an internalv combustion engine having. anair-fuelJmixture intale manifold and a mixture iiow controlling'throttle valve;

an infinitely variable friction drive comprising firstffriction elements, a iiuid coupling having an impeller driven by said'engine and a turbine, a planetary gear'unit comprising a power input element, a power output element and a reaction element, vone velement of -said gear unitheing connected to saidgturbine, clutch means for lconnecting two elements of said gear unit togetherv to establish a drive ratio through said gear unitof unity, second, fric-V tion elements connected to. driven portions of the;drive- Y line, third friction elements 'engageable with both said -first and said second friction elementsa'ndadapted thereby to establish a frictional driving. connectiontherebetween, iiuid pressure operated servo means including a;

by said engine is caused to operate at an approximately constant speed for 'any givenaccelerator.position.`

3. In al driveline fora wheeled vehicle, an internal combustion engine having .an air-fuel'mixture' intake manifold; and a mixture ow controlling throttle valve, an innitelyrvariable frictionA drive comprisingrst friction elements,4 ay fluid coupling having an impeller driven by'saidrengine and aturbine, a planetary gearunit comprising a power input'element, a power. output element and a reaction element, one element of said 'gear unit being connectedto said turbine and another element thereof being connected drivably to said first friction elements, first lclutch means for` connecting twoelements of said gear unit together to establish a drive ratio'through said gear unitof unity, secondrfriction elements connected to the driven portions ofksaiddriveline, thirdfriction ele-v ments'enga-geable with both said `first and said second friction elements and. adapted thereby to establish a fric-r tionall drivingronnection therebetween, fluid pressure operated :servo means including. a pressure operated piston for-varying the position of said third elements relative to saidfirst' and second Vele-rnents thereby providing an infinitely variable speed ratio change, a uid pressure source, conduit structure interconnecting said source. and saidservo means, valve means `disposed in and partly defining saidyconduitstructure for dist-ributing'pressure to spaced portions of said servo means includingan adjustable valve element adapted t-o effect a pressure unbalance across said pistonvin one direction'when it assumes one position and to effect `a pressure unbalance acrosstsaid piston in the opposite direction when it assumes another position, a personally operable accelerator, a calibrated` command mechanisminterconnecting said throttleV valve and said .accelerator whereby saidY engine is adapted to operate with the ratio `of transmission efiiciency tov-brake specific fuel consumption at an approximately maximum value for lany given engine speed, a motion-transmitting connection :between said"acc'eler`ator and vsaid valveelementfor urging the latter in Vone directionrwith a forcey thaty is related functionally Yinmagnitude to accelerator movement, an engine'drivenv iiuid pressure governor, a feedback mechanism including a pressure sensitive member connected to said valve element, anda fluid connection between said governor'and said pressure sensitive member for .subjecting the latter lto Va speed lsignal that opposes the effect'of the commandsignal imposed -by said command mechanism whereby said engine is caused to`operate at an approximately constant speed forany given accelera- `'tor position, a friction clutch means for connecting diyfor anchoring said reaction element during reverse drive operation when said first clutch means is released whereby said first friction elements are driven in a reverse direction.

4. In a ,driveline for a wheeled vehicle, an internal combustion engine having an air-fuel mixture intake manifold and a mixture flow controlling throttle valve, an infinitely variable friction drive comprising a plurality of friction element-s disposed in frictional driving relationship, a driving connection between said engine and one of .said friction elements, a companion friction element frictionally engaging said first friction element and connected drivably to a driven member, fluid pressure operated servo means including a pressure operated piston connected to one of said friction elements for varying the `point of contact of said one friction element with its companion friction element thereby providing an infinitely variable speed ratio change, a fluid pressure source, conduit structure interconnecting said source and said servo means, valve means disposed in and partly defining said conduit structure for distributing pressure to spaced portions of said servo means including van adjustable valve element adapted to effect a .pressure unbalance across said piston in one direction as it assumes one position and to effect a pressure unbalance across said piston in the opposite direction when it assumes another position, a 4personally operable accelerator, a calibrated command mechanism interconnecting said throttle valve and said accelerator whereby said engine 4is adapted to operate with the ratio of transmission efficiency to brake specific fuel consumption at an approximately maximum value, a command limiting network for establishing a motion transmitting connection between said accelerator and said valve element for urging theA latter in one direction with a force that is related functionally in magnitude to accelerator movement, said network including means for delaying the response of said valve means to movement of said accelerator, an engine driven fluid pressure governor, a feedback mechanism including a pressure sensitive member connected to said valve element and a fluid connection between said governor and said pressure sensitive member for subjecting the latter to a speed signal that opposes the effect of the command signal imposed by said command mechanism whereby the engine is caused to operate at an approximately constant kspeed for any viven accelerator position.

5. In a driveline for a wheeled vehicle, an internal combustion engine having an air-fuel mixture intake manifold and a mixture flow controlling throttle valve, lan infinitely variable friction drive comprising a plurality of friction elements disposed in frictional driving relationship, a driving connection between said engine and one of said friction elements, a companion friction element frictionally engaging said first friction element and defining therewith a torque delivery path, said companion friction velement being adjustable `in a direction transverse to the axis of rotation of said one friction element and being connected drivably to a driven member, fluid pressure operated servo means including `a pressure operated piston connected to said companion friction element for adjusting the point of contact of said first friction element kwith its companion friction element thereby providing an infinitely variable speed ratio change, a fluid pressure source, conduit structure interconnecting said source and said servo means, valve means disposed in and partly defining said conduit structure for distributing pressure to spaced portions of said servo means including an adjustable Valve element adapted to eect a pressure unbalance 4across said piston in one direction as it 'assumes one posi- `tion and to effect a pressure unbalance across said piston in the opposite direction when it assumes another posistion, a personally operable accelerator, a calibrated comlli mand mechanism interconnecting said throttle valve and said accelerator whereby said engine is adapted to operate with the ratio of transmission efiiciency to brake specific fuel consumption at an approximately maximum value, a command limiting network for establishing a motion transmitting connection between said accelerator and said valve element for urging the latter in one direction with a lfor-ce that is related functionally in magnitude to accelerator movement, said network including means for delaying the response of said valve means to movement of said accelerator, an engine driven fluid pressure governor, a feed back mechanism including a pressure sensitive member connected to said Valve lelement and a fluid connection between said governor and said .pressure sensitive member for subjecting the latter to a speed signal that opposes the effect of the command signal imposed by said command mechanism whereby said engine is caused to operate at a substantially constant speed for any given accelerator position, said network comprising a cam mechanically connected to said engine throttle, la cam follower engageable with said cam, a motion transmitting connection between said accelerator and said valve element for urging the latter in one direction with a force that is related functionally in magnitude to accelerator movement, spring means disposed between movable portions of said motion transmitting connection and said follower, and fluid dash ,pot means for opposing the biasing action of said spring means.

6. In a driveline for a wheeled vehicle, an internal combustion engine having an air-fuel mixture intake manifold and a mixture flow controlling throttle valve, an infinitely variable friction drive comprising a plurality of friction elements disposed in frictional driving relationship, a driving connection between said engine and one of said friction elements, a second friction element frictionally engaging said first friction element and a third friction element, said third friction element being connected drivably to a driven member, fluid pressure operated servo means including a pressure operated piston connected to said second friction element for varying the point of contact thereof with said first and third friction elements thereby providing an infinitely variable speed ratio change, a fluid pressure source, conduit structure interconnecting said source and said servo means, valve means disposed in and partly defining said conduit structure for distributing pressure to spaced portions of said servo means including an adjustable valve element adapted to effect a pressure unbalance across said piston in one direction as it assumes one position and to effect a pressure unbalance across said piston in the opposite direction when it assumes another position, a personally operable acelerator, a calibrated command mechanism interconnecting said throttle valve and said accelerator whereby said engine is adapted to operate with a brake specific fuel consumption of an aproximately minimum value, a command limiting network for establishing a motion-transmitting connection between said accelerator and said valve element for urging the latter in one direction with a force that is related functionally in magnitude to Aaccelerator movement, said network including means for delaying the response of said valve means to movement of said accelerator, an engine driven fluid pressure governor, a feed back mechanism including a pressure sensitive member connected to said valve element and a iiuid connection between said governor and said pressure sensitive member for subjecting the latter to a speed signal that opposes the effect of the command signal imposed by said command mechanism whereby said engine is caused to operate at an aproximately constant speed for any given accelerator position, said network comprising a cam mechanically connected to said egine throttle, a cam follower engageable with said cam, a motion transmitting connection between said accelerator and said valve element for urging the latter in one direction with a force that is related functionally in magnitude to accelerator move- `nor pressure signal.

'115 Y vment,'spring means disposed between movable portions of said motion transmittingfconnection and vsaid follower, and fluid dash pot means for opposing thev biasing action centrifugally responsive and adaptedy to establishapres'- sure signal that is relatedexponentially to engine speed,

and a non-linear spring means acting upon said pressure sensitive member to oppose the pressure jforce produced thereon-by saidfgovernor. pressure signal.

7. In a driveline for a wheeled vehicle,'an'internal com-` sername vof said spring means, said fluid pressure governor 4being tion when vit assumes anothery position, Va'prersonally operable accelerator, a calibrated commandmec'hanismin- Yterconnectin'g said throttle valvervlandg'said accelerator whereby said engine is adapted'to Voperate,Withlthe-ratio of transmissionjefiiciencyto brake'specic fuel consumption at an Aapproximately 'maximumvalue, vacommand limiting network for esttablishing a motion` transmitting connection between said'accelerator ,and `said y, valve ele-Y mentfor urging the latter inoneA direction with a force that'is related functionallyl in magnitude to accelerator movement, said network including means for delaying the ,n response of said valve means tofmovement 4of said yacdriveline, third friction elements engagable Wthvboth said first and said secondyfriction elements and adapted thereby to establishafrictional driving 'connection therebev tween, fluidrpressure operated servo means including-aV pressurey operated piston for varyingrtheV position Vof said' third elements relative to said rst and second elements, thereby providingan infinitely variable speed ratio change, a'uid p'ressuresource,conduit structure interconnecting said source and said servo means, valve means disposed in and partly defining said conduit structure for distributing pressure to spaced portions of said servo means includingA an adjustable valve element adapted to effect a pressureund balance across said piston in. one@ direction when it aslsumes 'one positionV and to. etfectfaf pressure unbalance acrossjsaid rpiston in the opposite direction when it assumes another. position, a personally operableaccelerator, .f

a calibratedk command mechanism interconnectingsaid throttle valve. and said accelerator whereby said engine yis adapted to operate with the ratioL of transmission eciency Ato brake specic fuel consumption atan -approximately Amaximum value for any given ,engine speed, a motion ltransmitting. connection betweensaid acceleratorand said valve'element for urging the latter in one direction lwith a force thatvis .related functionally in magnitude 'toj accelerator movement,r an engine driven uid pressure govr. ernor, a `feed back mechanism including a pressureV sensitive member connected to said valve element, a fluidconnectionbetween said governor and said 4member for subjecting the'latter to a speed signal .that opposes .the effect lof the command signal imposedby said command mechanism whereby said engine is caused to operate at an approximately constant speed for any given accelerator posit tion, said fluid pressuregovernor being centrifugally re-V Vsponsive and adapted tovestablish` a pressureysignal that'is related exponentially-to engine speed, and a non-linear spring means acting uponsaid pressure sensitive member to oppose a pressure force produced thereon by said gover- 8. In a driveline for a wheeled vehicle, an internal Vcom- Vbustion engine having anair-fuel mixture `intake manifold and ,a mixture flow controlling throttle valve, an

ininitely variable friction drive comprising a plurality 'of'friction elements disposed in frictional driving relationship, a vdriving connection between said engine and one lof said friction elements, a second Vfriction element'lfrictionally engaging said iirstfriction element'rk and a third friction element, saidthird 4friction element being con'- lnected drivably to a ldriven member, fluid pressure operated servo meansincluding apressure operated piston w means disposed in and partly definingrsaid conduit struc'- ture for Ydistributing pressure to spaced portions of said servo means including an adjustable valve element adapted to effect al pressure unbalance across said piston in-one direction asV it assumes one position andto effect a pres-V sure unbalance arQss said piston inthe opposite directo loppose said ygovernor pressure.

celerator, an engine drivenr fluid lpressure governor, a feed back .mechanism lincludingapressure sensitive memberconnected to said valve element and a fluid connection between said governor andsaid member for subjecting the latter to a speed signal that opposes the effect of the command signal Vimposed bygsaid command mechanism whereby saidy engine is 'caused-to operate at a substantially constant speed lfory any -givenv acceleratory position, said fluid pressure governorbeing centrifugally, responsive and adapted to establish a pressure signal that is relatedy exponentially to engine speed, and a lnon-linear spring means acting uponsaid pressure sensitive member to' oppose'the pressurejforce producedwthereon by said governor pressure signal. f

Y 9. In a ,driveline' for a wheeled vehicle, an internal interconnecting saidsource andsaid vservo means, valve means disposed in and vrpartlydefining saidpconduit Y structure'- for distributing pressure to spaced `portions of ysaid servomeans including an adjustable valve element adapted toV effect apressure unbalance across lsaid piston VvinV one direction when it assumes ,one position and to effect a pressure unbalance across said :piston inthe yopposite direction when it assumesV another'position, a

personally operable accelerator, a calibrated command mechanism interconnecting said throttle valve vand said accelerator whereby said engine is adaptedl to operate with the ratio of transmission efficiency `to brake specific fuel consumption at an approximatelyr maximum value for yany given engine speed, a motion transmitting connection between said accelerator and said valve element fo'rurgingrthe latter in 'one directionA with a force that is related functionally in magnitude to accelerator movement, an engine driven fluid pressure governor, a feed ,backv mechanism includingY a pressure sensitive member connected, to said valveV element, a fluid connection between said governor and saidmember for subjecting ,the latter to a speed signal that ,opposesy the effect of the lcommand Ysignal imposedrby said command mechanism .whereby Vsaid engine is, caused 'to operate at an approximately constant speed for any given accelerator position, a personally operable source of braking pressure, a braking pressure regulator valve in fluid cornmunication with saidlpressure source for establishing `a terconnectingusaid source Vand said servo means, valve A regulated pressure/[liet` is proportionalto the pressure establishedrbyfsaidbraking pressure source, and a uid connection between said braking pressure regulator valve Y andV saidv feed-back mechanism `whereby braking'pressure can befapplied to saidpressure sensitive member 10. In adriveline for a wheeled vehicle', aninternal rfriction elements connected to the driven portions of 'said driveline, third friction elements engageable with both said first and said second friction elements and adapted thereby to establish a frictional driving connection therebetween, uid pressure operated servo means y including a pressure operated piston for varying the position of said third elements relative to said first and second elements thereby providing an infinitely variable speed ratio change, a fluid pressure source, conduit structure interconnecting said source and said servo means, valve means disposed in and partly defining said conduit structure for distributing pressure to spaced portions of said servo means including an adjustable valve element adapted to effect a pressure unbalance across said piston in one direction when it assumes one position and to effect a pressure unbalance across said piston in the ,opposite direction when it assumes another position, a

personally operable accelerator, a calibrated command mechanism interconnecting said t-hrottle valve and said accelerator whereby said engine is adapted to operate Vwit-h the ratio :of transmission eiiiciency to brake specific fuel consumption at an approximately maximum value for any given engine speed, a motion transmitting connection between said accelerator and said valve element for urging the latter in one direction with a force that is related functionally in magnitude to accelerator movement, an engine driven uid pressure governor, a feed back mechanism includingr a pressure sensitive member connected to said valve element, a fluid connection between said governor and said member for subjecting the latter to a speed signal that opposes the effect of the command signal imposed by said command mechanism whereby said engine is caused to operate at a substantially constant speed for any given accelerator position, a personally operable source of braking pressure, a braking pressure regulator valve in Huid communication with said braking pressure source for establishing a regulated presure that is proportional yto the pressure established by said braking pressure source, a fluid connection between said braking pressure regulator valve and said feed-back mechanism whereby braking pressure can be applied to said pressure sensitive member to oppose said governor pressure and personally operable hill retard selector valve means for selectively interrupting fluid communication between the t braking pressure regulator valve and said feed-back mechanism.

11. In a driveline for a wheeled vehicle, an internal combustion engine having an air-fuel mixture intake manifold and a mixture flow controlling throttle valve, an infinitely Variable friction drive comprising a plurality of friction elements disposed in frictional driving relationship, a driving connection between said engine and one of said friction elements, a companion friction element frictionally engaging said first friction element and connected drivably to a driven member, fluid pressure operated servo means including a pressure operated piston connected to one of said friction elements for varying the point of contact of said one friction element with its companion friction element thereby providing an iniinitely variable speed ratio change, a fluid pressure source, conduit structure interconnecting said source and said servo means, valve means disposed in and partly defining said conduit structure for distributing pressure through spaced portions of said servo means including an adjustable valve element adapted to effect a pressure unbalance across said piston in one direction as it assumes one position and to effect a pressure unbalance across f said piston in the opposite direction when it assumes another position, a personally operable accelerator, a caliin one direction with a force that is related functionally in magnitude to accelerator movment, said network including means for delaying the response of said valve means to movement of said accelerator, an engine driven fluid pressure governor, a feed-back mechanism including a pressure sensitive member connected to said valve element and a fluid conection between said governor and said member for subjecting the latter to a Speed signal that opposes the effect of the command signal imposed by said command mechanism whereby said engine is caused to operate at an approximately constant speed for any given accelerator position, a personally operable source of braking pressure, a braking pressure regulator valve in fluid communication with said braking pressure source for establishing a regulated pressure that is proportional to the pressure established by said braking pressure source, a fluid connection between said braking pressure regulator valve and said feed-back mechanism whereby braking pressure can be applied to said pressure sensitive member to oppose said governor pressure.

12. In a driveline for a wheeled vehicle, an internal combustion engine having an air-fuel mixture intake manifold and a mixture ow controlling throttle valve, an infinitely variable friction drive comprising a plurality of friction elements disposed in frictional driving relationship, a driving connection between said engine and one of said friction elements, a companion friction element frictionally engaging said first friction element and connected drivably to a driven member, iiuid pressure operated servo means including a pressure operated piston connected to one of said friction elements for varying the point of contact of said one friction element with its companion friction element thereby providing an infinitely variable speed ratio change, a fluid pressure source, conduit structure interconnecting said source and said servo means, valve means disposed in and partly defining said conduit structure for distributing pressure through spaced portions of said servo means including an adjustable valve element adapted to effect a pressure unbalance across said piston in one direction as it assumes one position and to effect a pressure unbalance across said -piston in the opposite direction when it assumes another position, a personally operable accelerator, a calibrated command mechanism interconnecting said throttle valve and said accelerator whereby said engine is adapted to operate with the ratio of transmission efiiciency to brake specic fuel consumption at an approximately maximum value, a command limiting network for establishing a motion transmitting connection between said accelerator and said valve element for urging the latter in one direction with a force that is related functionally in magnitude to accelerator movement, said network including means for delaying the response of said valve means to movement of said accelerator, an engine driven fluid pressure governor, a feed back mechanism including a pressure sensitive member connected to said valve element and a fluid connection between said governor and said member for subjecting the latter to a speed signal that opposes the effect of the command signal imposed by said command mechanism whereby said engine is caused to operate at an approximately constant speed for any given accelerator position, a personally -operable source of braking pressure, a braking pressure regulator valve in fiuid communication with said braking pressure source for establishing a regulated pressure that is proportional to the ,pressure `established by said: braking `pressure source, a

huid connection between said' braking 'pressure vregulator operable hill retard selector valve rneansfor selectively interrupting Huidy communication tbetweenlsaid braking pressure regulator-valve :and said feed-back. mechanism.

15982147 y `'576-1J Panhard.y

Y '20 *i References-,Cited ltyfthdevExaminery jV l UNITEDVI STATES PATENTS r 5 3,094,203 6/63 f Jani@ en a1., '14e-472.1 x

DONA. WAITE, Primary '-Ezram'ner.V 

1. IN A DRIVELINE FOR A WHEELED VEHICLE, AN INTERNAL COMBUSTION ENGINE HAVING AN AIR-FUEL MIXTURE INTAKE MANIFOLD AND A MIXTURE FLOW CONTROLLING THROTTLE VALVE, AN INFINITELY VARIABLE FRICTION DRIVE COMPRISING FIRST FRICTION ELEMENTS DRIVABLY CONNECTED TO SAID ENGINE, SECOND FRICTION ELEMENTS CONNECTED TO DRIVEN PORTIONS OF THE DRIVELINE, THIRD FRICTION ELEMENTS ENGAGEABLE WITH BOTH SAID FIRST AND SAID SECOND FRICTION ELEMENTS AND ADAPTED THEREBY TO ESTABLISH A FRICTIONAL DRIVING CONNECTION THEREBETWEEN, FLUID PRESSURE OPERATED SERVO MEANS INCLUDING A PRESSURE OPERATED PISTON FOR VARYING THE POSITIONS OF SAID THIRD ELEMENTS RELATIVE TO SAID FIRST AND SECOND ELEMENTS THEREBY PROVIDING AN INFINITELY VARIABLE SPEED RATIO CHANGE, . A FLUID PRESSURE SOURCE, CONDUIT STRUCTURE INTERCONNECTING SAID SOURCE AND SAID SERVO MEANS, VALVE MEANS DISPOSED IN AND PARTLY DEFINING SAID CONDUIT STRUCTURE FOR DISTRIBUTING PRESSURE TO SPACED PORTIONS OF SAID SERVO MEANS INCLUDING AN ADJUSTABLE VALVE ELEMENTS ADAPTED TO EFFECT A PRESSURE UNBALANCE ACROSS SAID PISTON IN ONE DIRECTION WHEN IT ASSUMES ONE POSITION AND TO EFFECT A PRESSURE UNBALANCE ACROSS SAID PISTON IN THE OPPOSITE DIRECTION WHEN IT ASSUMES ANOTHER POSITION, A PERSONALLY OPERABLE ACCELERATOR, A CALIBRATED COMMAND MECHANISM INTERCONNECTING SAID THROTTLE VALVE AND SAID ACCELERATOR WHEREBY SAID ENGINE IS ADAPTED TO OPERATE WITH THE RATIO OF TRANSMISSION EFFICIENCY TO BRAKE SPECIFIC FUEL CONSUMPTION AT AN APPROXIMATELY MAXIMUM VALUE FOR ANY GIVEN ENGINE SPEED, A MOTION TRANSMITTING CONNECTION BETWEEN SAID ACCELERATOR AND SAID VALVE ELEMENT FOR URGING THE LATTER IN ONE DIRECTION WITH A FORCE THAT IS RELATED FUNCTIONALLY IN MAGNITUDE TO ACCELERATE MOVEMENT, AN ENGINE DRIVEN FLUID PRESSURE GOVERNOR, A FED BACK MECHANISM INCLUDING A PRESSURE SENSITIVE MEMBER CONNECTED T SAID VALVE ELEMENT, AND A FLUID CONNECTION BETWEEN SAID GOVERNOR AND SAID PRESSURE SENSITIVE MEMBER FOR SUBJECTING THE LATTER TO A SPEED SIGNAL THAT OPPOSES THE EFFECT OF THE COMMAND SIGNAL IMPOSED BY SAID COMMAND MECHANISM WHEREBY THE ENGINE IS CAUSED TO OPERATE AT AN APPROXIMATELY CONSTANT SPEED FOR ANY GIVEN ACCELERATOR POSITION. 